Container for transporting fresh water by sea

ABSTRACT

The invention relates to a container for transporting fresh water by sea, comprising a flexible covering for receiving fresh water and a pulling device which is joined to the flexible covering and made of a tubular retaining body which is used for coupling bridle lines. A rapid filling and emptying of the container is achieved in such a way that the tubular retaining body is enclosed at least partially by the flexible covering and that filling and emptying openings in the tubular retaining body open directly into the space enclosed by the flexible covering. The present invention further relates to a method for filling or unloading such a container.

BACKGROUND OF THE INVENTION

The invention relates to a container for transporting fresh water bysea, comprising a flexible covering for receiving fresh water and apulling device which is joined to the covering and is made of a tubularretaining body which is used for coupling bridle lines.

The economic transport of large quantities of fresh water by sea isgaining importance in order to supply water-starved regions close to thecoast with fresh water from regions close to the coast which have asurplus of water.

The sporadic supply of water to islands and zones close to the coastduring dry periods by means of tank ships has been carried out for manyyears, although this manner of supply is expensive and is cumbersome inloading and unloading. For some time there have been efforts to reducetransport costs by using floating, flexible containers which are pulledby small tugboats. All containers known and used in practice have theshape of a torpedo or boat and therefore have a quasi point-likefastening of the traction cable at the bow. This arrangement leads tostress peaks about said fastening point and thus often to thedestruction of the flexible container. Up until now it was only possibleto overcome these problems by limiting the maximum size of the flexiblecontainers, which in current practice are close to approx. 20,000 m³. Areduction in the transport costs can only be achieved by an increase inthe size of the flexible containers by more than 10 times the currentsize. The loading and unloading occurred up until now through hoses andthere are no special loading and unloading stations which have becomeknown for handling such large quantities of water in an economical way.

A floating container is known from GB 933 889 A which comprises aflexible covering which is held at one end by a cylinder outside of thecontainer. This may contribute to a certain extent to the distributionof mechanical forces. However, the filling and emptying of such acontainer is only possible via hoses or the like, as has been describedabove. A rapid loading and unloading of the containers in the loadingand unloading stations is not possible in this way.

SUMMARY OF THE INVENTION

It is the object of the present invention to provide a container whichenables a more economic transport of fresh water by sea. This is to beenabled on the one hand by an increase in the container volume incomparison with the convention containers, and on the other hand by amore rapid transshipment of the content of the container in loading andunloading stations.

These goals are achieved in accordance with the invention in such a waythat the tubular retaining body is at least partially enclosed by theflexible covering and that the filling and emptying openings arranged inthe tubular retaining body open directly into the space enclosed by theflexible covering. The relevant aspect of the solution in accordancewith the invention is that the tubular retaining body, which is used tointroduce the forces upon the flexible covering in such a way that adistribution over a large surface area is ensured, is also used forenabling an especially quick filling and emptying process. In this wayit is not only possible to realize containers with a very large volume,it is also possible to ensure a rapid transshipment at the coast andthus a short dwelling time at the end points of the transportationroute.

A favorable distribution of forces within the flexible covering can beachieved in such a way that the flexible covering is substantiallyrectangular in its layout in the empty state and that the tubularretaining body extends over the entire width of the flexible covering.

An increase in the load carrying ability of the flexible covering canpreferably by achieved in such a way that the flexible covering isarranged as a seamless hose. Weak points in the region of the seams arethus substantially avoided.

It is provided for, in a preferred embodiment of the invention, that thetubular retaining body comprises fastening brackets, which are arrangedon the one hand for fastening the bridle lines and on the other hand forarresting in a loading pontoon or an unloading pontoon. In this way itis possible to achieve an easy manipulation of the container from thetransport position to the loading or unloading position.

It is further preferable when a plurality of filling and emptyingopenings are arranged in a manner so as to be distributed over thelength of the tubular retaining body and that connecting pieces areprovided at the front region, for loading and unloading. An especiallyhigh flow rate can thus be achieved during filling or emptying.

For a simple manipulation of the container, and in accordance with apreferred embodiment of the present invention, it is advantageous whenthe retaining body assumes a predetermined height in the water. Theheight can preferably be set in such a way that a floating body isprovided on the tubular retaining body.

The invention further relates to a method for filling or emptying acontainer of the kind described above. In accordance with the invention,this method is characterized in that the tubular retaining body isconnected for filling purposes with a loading pontoon having acollecting tank for fresh water and that the collecting tank isconnected with the tubular retaining body for the transfer of freshwater. It is especially appropriate when the tubular retaining body isjoined with the loading pontoon via swiveling loading pipelines in orderto compensate the changing immersion depth of the retaining body.

A technically especially simple solution of the method in accordancewith the invention is given when during the filling of the container thefresh water is supplied via a loading tower into the loading pontoon,with the fresh water preferably being transferred from the loading towerto the loading pontoon in free fall.

The unloading can preferably be accelerated in such a way, that thecontainer is rolled up by a roll-up catamaran for performing theunloading process.

In order to dissipate the forces by wind and the motion of the sea,which act upon a large container, it is preferable that when the tubularretaining body is fastened via the bridle lines to the unloading pontoonduring the emptying of the container. It is especially appropriate inthis connection when the loading pontoon is held in a manner so as to beswiveling around a loading tower during the emptying of the container.The same applies in an analogous manner to the filling of the container.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is now explained in closer detail by reference to theembodiments shown in the drawings, wherein:

FIG. 1 a shows a schematic representation in a side view of a containerin accordance with the invention which is pulled by a tugboat;

FIG. 1 b shows the container of FIG. 1 a in a top view;

FIG. 2 a shows an embodiment of the invention in a side view duringtransport in the empty state;

FIG. 2 b shows the embodiment of FIG. 2 a in a top view during thetransport in the empty state;

FIG. 3 a shows a view of a detail of an apparatus in accordance with theinvention in a top view;

FIG. 3 b shows a sectional view along line IIIb—IIIb in FIG. 3 a

FIG. 4 a shows a side view of a container in accordance with theinvention in a loading station;

FIG. 4 b shows a view according to FIG. 4 a from above;

FIG. 5 a shows a container in accordance with the invention in anunloading station in a side view, and

FIG. 5 b shows a view according to FIG. 5 a from above.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 a and 1 b show a container in accordance with the inventionduring the transport in the filled state. A tugboat 1 is connected withthe container via a hawser 7 and two bridle lines 6 which are fastenedto brackets 5 of a retaining body 2 which is configured substantially inthe shape of a tube. A hose-like flexible covering 3 is fastened to theretaining body 2 which in the top view is substantially rectangular andis filled with fresh water. At the end of the flexible covering 3,opposite of the retaining body 2, an end pipe 4 is provided which isalso arranged in the shape of a cylinder and which closes off theflexible covering 3. Through bridle lines 36 the illustrated containercan be coupled to a tugboat.

FIGS. 2 a and 2 b show the transport of a container in accordance withthe invention in the emptied state. The flexible covering 3 is wound upon the end pipe 4 and the retaining body 2 is situated directly adjacentto said wound covering. In order to minimize traveling resistance, thecontainer is pulled in the axial direction of the retaining body 2 orthe end pipe 4.

FIGS. 3 a and 3 b show the retaining body 2 in detail. In the region ofthe retaining body 2, which is oriented towards the interior of theflexible covering 3 (not shown here), a plurality of filling andemptying openings 12 are provided through which fresh water can flowfrom the inner space of the retaining body 2 to the interior space ofthe flexible covering 3. The supply of fresh water to the interior ofthe retaining body 2 occurs via connecting pieces 35.

FIGS. 4 a and 4 b show the filling process of the container inaccordance with the invention. The fresh water flows via a feed pipeline32 into a cylindrically configured loading tower 13 whose upper sidecomprises an outlet 20 from which the fresh water is allowed to flow outin free fall. A ring 14 is arranged in a height-adjustable fashion onthe loading tower 13. A loading pontoon 8 is fastened to said ring bymeans of a cable 34 and an interposed fender 15. A collecting tank 21 isarranged in the loading pontoon 21 in which the fresh water is collectedfrom the outlet 20. A venting tank 18 is adjacent to the collecting tank21 which is used to remove the air introduced into the fresh water.

Laterally swiveling docking arms 16 are attached to the loading pontoon8 onto which the retaining body 2 of the container can be docked.Docking arms 16 swivelling together with the loading pipelines 19 areprovided through which the fresh water flows from the venting tank 18 tothe retaining body 2.

The entire arrangement consisting of the loading pontoon 8 and thecontainer in accordance with the invention, which is coupled to thesame, is swivelling around the vertical axis of the loading tower 13during the loading process according to weather condition and changingin height according to the sea level. Cables securing lines 34 areprovided for fixing the loading pontoon to the loading tower and can beloosened in the case of storms in order to avoid any damage to thecontainer. As a result of the flexibility it is reliably prevented thateven in the case of heavy sea or storms inadmissibly large forces willbe exerted on the loading tower 13 or the loading pontoon 8 which couldlead to damage.

FIGS. 5 a and 5 b show the unloading process of the container inaccordance with the invention. A roll-up catamaran 33 is provided forrolling up the flexible covering 3 of the container on the end pipe 4.The rolling-up process is secured by end disks 39 which are attached tothe side of the end pipe 4. During unloading, the retaining body 2 isfastened to the docking arms 25 and the container is emptied viaunloading pipelines 28. The docking arms 25 and the unloading pipelines28 are swivelably fastened to an unloading pontoon 9, which contains acollecting tank 27. Several submerged pumps 29 are installed in thecollecting tank 27, pumping the fresh water through pipelines 30 whichare fastened to a supporting frame 31. The fresh water flows from thepipeline 30 in free fall into an unloading tower 22 and flows from therevia pipeline 37 to shore.

In analogy to the loading pontoon 8, the unloading pontoon 9 is fastenedto a ring 23 via a fender 24, which ring slides in a rotatable andheight-adjustable manner on the unloading tower 22. A fender 24 is usedto keep the unloading pontoon 9 at a predetermined distance from theunloading tower 22.

FIGS. 4 a and 5 a show with phantom lines a position of the docking arms16 and 25 plus attached retaining body 2 before the loading process hasstarted and after the unloading process has finished. For distinctionpurposes the retaining body 2 is designated here with 2*. Thisrepresentation shows the swivelability of the docking arms 16 around theaxis 17 and the swivelability of the docking arms 25 around the axis 26.

The unloading pontoon 9 is provided with a sufficiently strong powersupply for the operation of its pumps and winches in order to secure afast emptying. This fast emptying is achieved in particular in such away that the water from the interior of the flexible covering 3 can flowinto the retaining body 2 via the filling and emptying openings 12 or,vice versa, in the case of filling from the retaining body 2 via thefilling and emptying openings 12 into the flexible covering 3.

The use of the roll-up catamaran 33 allows the water to flow from theflexible covering 3 into the collecting tank 27 without using any pumps.

1. A container for transporting fresh water by sea, comprising aflexible covering for receiving fresh water and a pulling device whichis joined to the flexible covering, which comprises a tubular retainingbody and which is used for coupling bridle lines, wherein the tubularretaining body is enclosed at least partially by the flexible coveringand filling and emptying openings in the tubular retaining body opendirectly into a space enclosed by the flexible covering wherein aplurality of said filling and emptying openings are arranged in a mannerso as to be distributed over the length of the tubular retaining bodyand that connecting pieces are provided on a front side of the tubularretaining body, and connecting pieces are configured, and open to anoutside region opposite to the flexible coverings.
 2. A container asclaimed in claim 1, wherein the flexible covering is substantiallyrectangular in its layout in the empty state and that the tubularretaining body extends over the entire width of the flexible covering.3. A container as claimed in claim 1, wherein the flexible covering isconfigured as a seamless hose.
 4. A container as claimed in claim 1,wherein at an end of the flexible covering which is distal from thetubular retaining body an end pipe is provided which comprises enddisks.
 5. A container as claimed in claim 1, wherein the tubularretaining body comprises fastening brackets which are configured on theone hand for fastening the bridle lines and on the other hand forarresting in a loading pontoon or an unloading pontoon.
 6. A method forfilling and emptying a container for transporting fresh water by sea,comprising the steps of: joining a flexible covering for receiving freshwater and a pulling device to one another, wherein the flexible coveringcomprises a tubular retaining body, and joining the tubular retainingbody together with a loading pontoon having a collecting tank for freshwater, wherein and that the collecting tank is connected with thetubular retaining body for transferring fresh water; separating thetubular retaining body from the loading pontoon; joining the tubularretaining body with an unloading pontoon for emptying the container,wherein the unloading pontoon comprises a collecting tank for freshwater; and connecting the collecting tank with the tubular retainingbody for the transfer of fresh water; wherein the container is rolled upby a roll-up catamaran in order to perform an unloading process.
 7. Amethod as claimed in claim 6, wherein the tubular retaining body isconnected via swiveling loading pipelines with the loading pontoon inorder to compensate the fluctuating immersion depth of the tubularretaining body.
 8. A method as claimed in claim 6, wherein the tubularretaining body is fastened via bridle lines to the loading pontoonduring filling of the container.
 9. A method as claimed in claim 6,wherein the loading pontoon is held swiveling about a loading towerduring loading of the container.
 10. A method as claimed in claim 6,wherein the loading pontoon is held remote from a loading tower by afender during loading of the container.
 11. A method as claimed in claim6, wherein during the filling of the container the fresh water issupplied via a loading tower to the loading pontoon, with the freshwater being transferred in free fall from the loading tower to theloading pontoon.
 12. A method as claimed in claim 6, wherein the tubularretaining body is connected via swiveling unloading pipelines with theunloading pontoon in order to provide compensation for a fluctuatingimmersion depth of the retaining body.
 13. A method as claimed in claim6, wherein the tubular retaining body is fastened to the unloadingpontoon via the bridle lines during unloading of the container.
 14. Amethod as claimed in claim 6, wherein the unloading pontoon is heldswivelably about an unloading tower during unloading of the container.15. A method as claimed in claim 6, wherein the unloading pontoon isheld remote from an unloading tower by means of a fender duringunloading of the container.
 16. A method as claimed in claim 6, whereinduring unloading of the container the fresh water is supplied from theunloading pontoon to an unloading tower, with the fresh water beingtransferred in free fall from the unloading pontoon to the unloadingtower.